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authorMichal Marek <mmarek@suse.com>2015-08-19 17:36:41 +0200
committerMichal Marek <mmarek@suse.com>2015-09-04 13:14:10 +0200
commit5631d9c429857194bd55d7bcd8fa5bdd1a9899a3 (patch)
treef0424c4fe42eb83bf35a0cda4204aff097a8b192
parentd179e22762fd38414c4108acedd5feca4cf7e0d8 (diff)
kbuild: Fix clang detection
We cannot detect clang before including the arch Makefile, because that can set the default cross compiler. We also cannot detect clang after including the arch Makefile, because powerpc wants to know about clang. Solve this by using an deferred variable. This costs us a few shell invocations, but this is only a constant number. Reported-by: Behan Webster <behanw@converseincode.com> Reported-by: Anton Blanchard <anton@samba.org> Signed-off-by: Michal Marek <mmarek@suse.com>
-rw-r--r--Makefile9
-rw-r--r--arch/powerpc/Makefile8
-rw-r--r--scripts/Kbuild.include4
-rw-r--r--scripts/Makefile.extrawarn2
4 files changed, 10 insertions, 13 deletions
diff --git a/Makefile b/Makefile
index 13270c0a9336..5ccbb58553ab 100644
--- a/Makefile
+++ b/Makefile
@@ -661,14 +661,7 @@ endif
endif
KBUILD_CFLAGS += $(stackp-flag)
-ifeq ($(shell $(CC) -v 2>&1 | grep -c "clang version"), 1)
-COMPILER := clang
-else
-COMPILER := gcc
-endif
-export COMPILER
-
-ifeq ($(COMPILER),clang)
+ifeq ($(cc-name),clang)
KBUILD_CPPFLAGS += $(call cc-option,-Qunused-arguments,)
KBUILD_CPPFLAGS += $(call cc-option,-Wno-unknown-warning-option,)
KBUILD_CFLAGS += $(call cc-disable-warning, unused-variable)
diff --git a/arch/powerpc/Makefile b/arch/powerpc/Makefile
index 05f464eb6952..dfe88896b06c 100644
--- a/arch/powerpc/Makefile
+++ b/arch/powerpc/Makefile
@@ -67,7 +67,7 @@ UTS_MACHINE := $(OLDARCH)
ifeq ($(CONFIG_CPU_LITTLE_ENDIAN),y)
override CC += -mlittle-endian
-ifneq ($(COMPILER),clang)
+ifneq ($(cc-name),clang)
override CC += -mno-strict-align
endif
override AS += -mlittle-endian
@@ -333,7 +333,7 @@ TOUT := .tmp_gas_check
# - Require gcc 4.0 or above on 64-bit
# - gcc-4.2.0 has issues compiling modules on 64-bit
checkbin:
- @if test "${COMPILER}" != "clang" \
+ @if test "$(cc-name)" != "clang" \
&& test "$(cc-version)" = "0304" ; then \
if ! /bin/echo mftb 5 | $(AS) -v -mppc -many -o $(TOUT) >/dev/null 2>&1 ; then \
echo -n '*** ${VERSION}.${PATCHLEVEL} kernels no longer build '; \
@@ -342,14 +342,14 @@ checkbin:
false; \
fi ; \
fi
- @if test "${COMPILER}" != "clang" \
+ @if test "$(cc-name)" != "clang" \
&& test "$(cc-version)" -lt "0400" \
&& test "x${CONFIG_PPC64}" = "xy" ; then \
echo -n "Sorry, GCC v4.0 or above is required to build " ; \
echo "the 64-bit powerpc kernel." ; \
false ; \
fi
- @if test "${COMPILER}" != "clang" \
+ @if test "$(cc-name)" != "clang" \
&& test "$(cc-fullversion)" = "040200" \
&& test "x${CONFIG_MODULES}${CONFIG_PPC64}" = "xyy" ; then \
echo -n '*** GCC-4.2.0 cannot compile the 64-bit powerpc ' ; \
diff --git a/scripts/Kbuild.include b/scripts/Kbuild.include
index d3437b82ac25..3523df613391 100644
--- a/scripts/Kbuild.include
+++ b/scripts/Kbuild.include
@@ -128,6 +128,10 @@ cc-option-align = $(subst -functions=0,,\
cc-disable-warning = $(call try-run,\
$(CC) $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS) -W$(strip $(1)) -c -x c /dev/null -o "$$TMP",-Wno-$(strip $(1)))
+# cc-name
+# Expands to either gcc or clang
+cc-name = $(shell $(CC) -v 2>&1 | grep -q "clang version" && echo clang || echo gcc)
+
# cc-version
cc-version = $(shell $(CONFIG_SHELL) $(srctree)/scripts/gcc-version.sh $(CC))
diff --git a/scripts/Makefile.extrawarn b/scripts/Makefile.extrawarn
index f734033af219..4efedcbe4165 100644
--- a/scripts/Makefile.extrawarn
+++ b/scripts/Makefile.extrawarn
@@ -56,7 +56,7 @@ endif
KBUILD_CFLAGS += $(warning)
else
-ifeq ($(COMPILER),clang)
+ifeq ($(cc-name),clang)
KBUILD_CFLAGS += $(call cc-disable-warning, initializer-overrides)
KBUILD_CFLAGS += $(call cc-disable-warning, unused-value)
KBUILD_CFLAGS += $(call cc-disable-warning, format)

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